Year	Percent
1960-01-01	61.5272845831765
1961-01-01	60.8784902545045
1962-01-01	61.4767732190503
1963-01-01	61.4809700780306
1964-01-01	61.7963129128850
1965-01-01	62.4124251025503
1966-01-01	63.3798670880511
1967-01-01	63.8016905139194
1968-01-01	64.0806799419813
1969-01-01	64.6146680947593
1970-01-01	63.9926308534091
1971-01-01	63.1752480770041
1972-01-01	63.7738037158897
1973-01-01	64.8524862554212
1974-01-01	64.9955436611056
1975-01-01	63.0888157813432
1976-01-01	64.1475237187040
1977-01-01	65.3952589430036
1978-01-01	67.0988253249408
1979-01-01	67.9123889032224
1980-01-01	67.1859338772213
1981-01-01	67.0785616345151
1982-01-01	65.7685132792469
1983-01-01	66.0058859260244
1984-01-01	68.1339867956146
1985-01-01	69.0004449294830
1986-01-01	69.6815303973802
1987-01-01	70.7406539567569
1988-01-01	71.6463395193762
1989-01-01	72.4952027678994
1990-01-01	72.1916626426863
1991-01-01	70.9676129954728
1992-01-01	70.8058542042777
1993-01-01	71.2078274457061
1994-01-01	72.0017585140024
1995-01-01	72.5348943689197
1996-01-01	72.8587514144424
1997-01-01	73.5020446879446
1998-01-01	73.8434506953651
1999-01-01	73.9460516443015
2000-01-01	74.0945614676400
2001-01-01	73.1356183335720
2002-01-01	71.9293100890772
2003-01-01	71.2233428948911
2004-01-01	71.2224827839444
2005-01-01	71.5301723793347
2006-01-01	71.9970749367823
2007-01-01	71.7813159499610
2008-01-01	70.8882497236440
2009-01-01	67.6259496602844
2010-01-01	66.6897631361958
2011-01-01	66.6475446038349
2012-01-01	67.1366115527527
2013-01-01	67.3599398337765
2014-01-01	68.1487492195523
2015-01-01	68.7096181930347
2016-01-01	69.3513529394714
2017-01-01	70.1101655245488